I'm slowly converting to Ray Jardine's philosophies - again.
The evening, I chopped up yet another Ridgerest closed-cell foam pad into a torso-shaped pad. This version weighed in at 103 grams - 3.63 ounces. The dimensions are similar to BackpackingLight.com's Torsolite, which a) will be back in stock soon; and b) has been selling like hotcakes recently on BPL's gear trade forum.
This is my second attempt at hacking down a CCF pad into a torso-shaped bundle. My first attempt still exists - it is rectangular at 29.5x19.5 and about ~5.4 oz. When I saw that BPL was going to get more TorsoLites in stock, I through about the unused pad on my sides, especially flanking by buttocks. So I hacked this one down and lost almost 2 oz.
It's going out for its first test this weekend, somewhere in Minnesota that lacks mosquitoes. When I return, I imagine I'll cut a concave curve into the sides near my true waist to chop out even more unused pad. Until then, the pad will stay nicely above 100 grams.
As a final note, the only company that sells torso-length pads is GossamerGear. Unmodified, these pads weigh in at 3.5-3.8 oz, and are also rectangular. Not too shabby.